From: Willy Tarreau <w@1wt.eu>
Date: Mon, 18 Mar 2019 15:31:18 +0000 (+0100)
Subject: BUILD: tools: fix a build warning on some 32-bit archs
X-Git-Tag: v2.0-dev2~40
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=9b6be3bbeb40a4e606980f70fe2a8db64c33a44e;p=thirdparty%2Fhaproxy.git

BUILD: tools: fix a build warning on some 32-bit archs

Some recent versions of gcc apparently can detect that x >> 32 will not
work on a 32-bit architecture, but are failing to see that the code will
not be built since it's enclosed in "if (sizeof(LONG) > 4)" or equivalent.
Just shift right twice by 16 bits in this case, the compiler correctly
replaces it by a single 32-bit shift.

No backport is needed.
---

diff --git a/src/standard.c b/src/standard.c
index 2bc4405fb7..03072b96b9 100644
--- a/src/standard.c
+++ b/src/standard.c
@@ -2672,7 +2672,8 @@ unsigned int mask_find_rank_bit(unsigned int r, unsigned long m)
 	t = 0;
 	s = LONGBITS;
 	if (s > 32) {
-		t = (d >> 32) + (d >> 48);
+		unsigned long d2 = (d >> 16) >> 16;
+		t = d2 + (d2 >> 16);
 		s -= ((t - r) & 256) >> 3; r -= (t & ((t - r) >> 8));
 	}
 
@@ -2706,7 +2707,8 @@ unsigned int mask_find_rank_bit_fast(unsigned int r, unsigned long m,
 	t = 0;
 	s = LONGBITS;
 	if (s > 32) {
-		t = (d >> 32) + (d >> 48);
+		unsigned long d2 = (d >> 16) >> 16;
+		t = d2 + (d2 >> 16);
 		s -= ((t - r) & 256) >> 3; r -= (t & ((t - r) >> 8));
 	}